function(doc) {
  if (doc.createdAt) {
      var d = new Date(doc.createdAt * 1000);
      var getOldDate = function (d) {
          function f(n) {
              // Format integers to have at least two digits.
              return n < 10 ? '0' + n : n;
          }
          return d.getUTCFullYear()   + '-' +
               f(d.getUTCMonth() + 1) + '-' +
               f(d.getUTCDate())      + 'T' +
               f(d.getUTCHours())     + ':' +
               f(d.getUTCMinutes())   + ':' +
               f(d.getUTCSeconds())   + 'Z';
      }

      emit(getOldDate(d), {email: doc.email, firstname: doc.firstname, lastname:doc.lastname});
  }
}